DESCRIPTION (Adapted from the Applicant Abstract): The adjustment process for breast cancer survivors may be burdensome and lengthy. There is also ample evidence from the psychoneuroimmunology (PNI) literature showing that adults undergoing acute and/or long term stressors experience high rates of adjustment difficulties and important biologic effects--persistent down regulation of the immune system. Thus, deteriorations in quality of life (QOL) with cancer are underscored if they also have adverse health effects. In the general case, the immune system may be relevant to host resistance against progression and metastatic spread, but cancers etiologically linked to hormonal stimuli--such as breast cancer--may be particularly responsive to adverse, down-regulating factors. To guide the research, a biobehavioral model of cancer stress and disease course is proposed. This model includes psychological (stress and quality of life), behavioral (health behaviors and compliance), and biologic (immune) factors, and specifies the pathways by which health outcomes (eg. disease endpoints--recurrence, disease-free interval) might be affected. We propose to test portions of the model with an experiment--a randomized clinical trial of a psychological intervention. Women with Stage II or III breast cancer will be randomized between psychological behavioral intervention and no intervention arms. Our hypothesis is that women being treated with the psychological intervention protocol will show lowered stress, increased QOL, more positive health behaviors and fewer negative ones, greater compliance, and an increase in immune functioning. In turn, we also anticipate that they will show a doubling (ratio of median duration=2)in time to recurrence, with a .05 level of significance and power of 0.80, one-sided test. Data from this proposal will provide 1) a test of a psychological intervention which is designed to reduce stress, enhance quality of life, increase positive health behaviors, decrease negative health behaviors, and improve compliance; 2) a test of the immune enhancing effects of such interventions; 3) a test of the health (cancer Outcome) consequences of such interventions; and, 4) a test of immunity as one mechanism which may link psychological/behavioral variables to cancer outcomes.